I was born and raised in Wichita, Kansas, the prairie. What we have is land. Lots of it. Space for roads and parking lots and sidewalks broad enough that nobody has to negotiate much of anything.

The sidewalks I remember were wide enough for someone walking a dog to pass a family of four without either party thinking much about the arrangement. There was room. You could be considerate without having to do anything.

Chestnut Hill asks a little more of you.

On a narrow sidewalk, people approaching one another have to work something out. A shoulder turns. A couple briefly becomes a line. Somebody pauses to let a stroller through. Most of this happens without discussion, and when it works, you barely notice it.

I spend a lot of time running through the neighborhood, which puts me fairly low in what I think of as the hierarchy of deference on a sidewalk.

Children get space. Elderly people get space. People with disabilities get space. People pushing strollers get space. Anyone who clearly has a harder time maneuvering than I do gets space. I’m a healthy adult out here voluntarily making himself tired. I can move. It is, after all, a sidewalk, not a side-run.

I typically take issue with groups. Four adults or more, walking shoulder to shoulder, engrossed in conversation and occupying the entire width of the pavement. My wife and I encounter them on evening walks. I encounter them running. As we approach each other, I begin calculating where I’m going to go.

Grass. Flower bed. Curb. Germantown Avenue, an option whose drawbacks are currently driving past. Surely, somebody will move over. I’m in the correct lane. There are no lanes, of course. But I am in the correct one.

Sometimes nobody adjusts. I move, the group passes, and the physical encounter is over. The discussion in my head can last considerably longer. Was I not seen? Did they see me and decide that making room was entirely my responsibility? How can four people all arrive at the same conclusion?

I have very little evidence about any of this. Usually, by then, I have an excellent view of the backs of their heads. What bothers me, I think, is less the inconvenience than the missing acknowledgment.

One person falling half a step behind another would do it. A slight turn of the shoulder. Some indication that we have all noticed there is another human being here and that the available pavement has not expanded to accommodate him. I don’t expect thanks every time I step aside. Although, considering the amount of thought I’ve devoted to the subject, perhaps I am expecting something.

There is also a problem with my hierarchy. It seems perfectly sensible to me, naturally, because I invented it. But I assign people their places in it after looking at them for perhaps three seconds.

A stroller is easy to see. Pain isn’t always. Neither is exhaustion. Or injury. Or grief. Or distraction. Or whatever private trouble somebody might be carrying through an otherwise ordinary Tuesday afternoon.

I know my own legs are working. That is about the extent of my medical knowledge of the situation. Still, four adults do not ordinarily need to remain abreast while passing another person. I would like to hold on to that modest proposition without turning an evening walk into an investigation of what has gone wrong with society.

That is the harder part.

Irritation is remarkably productive. Give me 30 seconds and I will construct an entire theory of human behavior. I will take one inconsiderate stranger and appoint him representative of his generation, his neighborhood, perhaps civilization.

Meanwhile, the stranger has turned the corner and forgotten I exist. I carry the whole case alone. There are, of course, other possibilities. Maybe the people approaching me haven’t seen one another in years. Maybe somebody is telling a story worth hearing. Maybe they’re tired. Maybe they simply haven’t noticed how much room they are taking up.

They don’t need some hidden tragedy to earn a little uncertainty from me. And sometimes they may simply be inconsiderate. That possibility survives all this reflection.

I can believe somebody should have moved over without continuing to prosecute the case for the next 20 minutes, during which they are absent and I am supposedly enjoying myself outside.

Recently, near Germantown Avenue and Cresheim Valley Drive, I watched a woman wearing headphones and a backpack nearly step into the path of a speeding truck. The truck had the green light. A mother nearby, standing with her child, saw it happening too.

The woman stopped. The truck went through. Nothing happened, which was the good part. Afterward, the mother and I made eye contact and smiled. I can’t say exactly what was in her smile. Relief, probably. A little disbelief. But for a moment our attention had gone to exactly the same place.

We didn’t know the woman. We didn’t know each other. There had been no negotiation over whose responsibility she was. Nobody had to calculate who should move first or who had the right of way in some larger moral sense. We simply wanted her not to get hit by a truck.

I have thought about that look a lot. It belongs somewhere in my accounting of the neighborhood. So do all the uneventful passages I barely notice: the stranger who steps aside before I do, the couple who falls naturally into single file, the person who pauses for half a second and makes enough room for both of us to continue without breaking stride.

Those moments disappear almost immediately. The group that doesn’t move can occupy three blocks of my attention. The person who does may be forgotten before the next corner. There is probably something worth noticing in that.

I still like living somewhere I encounter people on foot. I like running these streets. I like walking them with my wife. I like the old stone walls, the trees, the houses, the people, even Germantown Avenue with its occasional suggestion that crossing it requires both timing and faith.

These are things I can lose track of while mentally composing a complaint about the conditions under which I am enjoying them. The irritation will come again. I know that.

Four people will appear ahead of me, arranged across the sidewalk like a defensive line. I will see them. They will see me. Or they won’t. I will begin calculating. Grass. Curb. Street. Surely somebody will move. Maybe somebody will. Maybe nobody will. Either way, there will eventually be room enough to get past. And then I can decide how much farther I want to carry them with me.

Most days, I’d rather get back into my stride.

Sam Beckett is a Chestnut Hill resident.